1. Field of the Invention
The present invention relates to a linear motor suitable for driving a stage apparatus applied to an exposure apparatus used in the semiconductor manufacturing process.
2. Related Background Art
FIG. 10 shows the layout of permanent magnets used in a conventional linear motor. FIG. 10 shows only one of opposing permanent magnet groups. In FIG. 10, permanent magnets 10a to 10c are arrayed on a yoke 4. Each permanent magnet has a non-rectangular parallelopiped shape formed by cutting off the corner portions. The plurality of permanent magnets 10a to 10c are arrayed so that poles of opposite polarities (N and S poles) alternately appear, and the thicknesses and widths of the individual permanent magnets are determined so as to generate a sine magnetic field in the space between the opposing stator groups.